Shinko Microelectronics, a Japanese firm based in Dublin, is expected to announce the closure of its Tallaght facility tomorrow, resulting in the loss of 350 jobs.
Senior Japanese executives are flying to Dublin and have scheduled a meeting with the Tánaiste, Ms Harney, and IDA Ireland officials, to announce the results of a company-wide review.
In a separate development, Altavista, one of the world's first internet search engines, said yesterday it would shut its Dublin-based European finance office, with the loss of 10 jobs.
The company is making 160 staff redundant worldwide and closing its online shopping service based in the US.
The closure of Altavista's office, which was forecast to expand to employ 30 people this year, together with job losses at Shinko, are further blows to the high-tech sector. However, Altavista's fortunes have slumped along with the internet sector.
Shinko, a joint venture between Fujitsu and Shinko Electronics, has had an operation in the Republic since 1980. It produces electronic components and memory semiconductors for the mobile phone market in Europe and Asia. It also served as a key European logic subcontracting base for Shinko Electric.
In 1999, it announced plans to invest £70 million in a new factory in Dublin but subsequently put these on hold.